The proposed work is a direct continuation of the studies on the insulin-sensitive glucoregulator center of the CNS that was carried out in our laboratories during the past five years. We have observed that intracarotid injection of doses of insulin, too small to cause any changes if injected intravenously, resulted in a rapid fall of the blood glucose. Assuming that the change in the systemic blood glucose was mediated through a neural receptor center, we endeavored to investigate the location, mode of action (i.e., signal perception, transmission, efferet fibres, effector organ) of this center. Chemical and stereotoxic surgical lesioning, as well as the binding of radio-labeled insulin are utilized for the localization of the insulin receptor center, and specific inhibitors of neural transmission mechanisms are employed to study the efferent fibres of this glucoregulator system. Investigations of the functional impairment of the insulin sensitive CNS glucoregulator system in experimental conditions, that resemble human disease states (obesity, hyperinsulinemia, diabetes mellitus), serve to assess the clinical relevance of the above observations.